Amine derivatives of copolymers of alpha, beta-unsaturated polycarboxylic acids



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United States Patent AlVIINE DERIVATIVES OF COPOLYMERS OF ALPHA,BETA-UNSAT URATED POLYCAR- BOXYLIC ACIDS John J. Giammal'ia, Woodbury,N. J., assignor to Socony- Vacuum Oil Company, Incorporated, acorporation of New York No Drawing. Original application November 14,1949, Serial No. 127,266. Divided and this application April 3, 1951,Serial No. 219,122

1 Claim. (Cl. 26078) This invention relates generally to improvedlubricating oil compositions. More particularly, it relates tolubrieating oil compositions containing aliphatic amine derivatives ofcopolymers of :alpha, beta-unsaturated polycarboxylic acids oranhydrides with aliphatic vinyl compounds as pour point depressants andviscosity index irnprovers.

The copolymerization of alpha, beta-unsaturated polycarboxylic acids, oranhydrides, with certain aliphatic vinyl compounds and the reaction ofthe copolymer products with primary and secondary amines, to form aminederivatives thereof, has been described in the prior art. However,insofar as is known, it has never before been suggested that any ofthese derivatives are useful as additives for lubricating oils.

We have now found that copolymers produced by copolymerizing an alpha,beta-unsaturated polybasic acid, or anhydride, such as maleic anhydride,with an aliphatic vinyl compound, such as a vinyl ester, vinyl ether,acrylic ester, allyl ether, allyl ester or an alpha olefin, may bereacted with relatively long-chain primary or secondary aliphatic aminesto form imide or amide derivatives which are efiective as viscosityindex improvers and pour point depressants in lubricating oils. It is,therefore, the primary object of this invention to provide improvedlubricating oil compositions containing such copolymeramine derivatives.Other and further objects will be apparent from the following detaileddescription of the invention.

As already indicated, the .amine derivatives of the copolymers, ascontemplated herein, are prepared by first copolymerizing the alpha,beta-unsaturated polybasic acid, or anhydride, with the aliphatic vinylcompound and then reacting the copolymer product with the primary orsecondary aliphatic amine.

The alpha, beta-unsaturated acids contemplated for use herein, includemaleic, fumaric, itaconic, citraconic, glutaconic, mesaconic andaconitic acids and their anhydrides, maleic anhydride being particularlypreferred because it is the least expensive and because the productsobtained by its use are, as a rule, more eifective than those obtainedwith the other acids and anhydrides.

vAs non-limiting examples of the aliphatic vinyl compounds suitable foruse in the polymerization reaction, the following may be mentioned:

(a) Vinyl ethers, such as vinyl ethyl ether, vinyl butyl ether, vinyloctyl ether, vinyl dodecyl ether, vinyl tetradecyl ether, vinylhexadecyl ether, vinyl octadecyl ether, vinyl ethenyl ether, vinyloctenyl ether, vinyl tetradecenyl ether, vinyl octadecenyl ether;

(1;) Vinyl esters, such as vinyl acetate, vinyl butyrate, vinylcaprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinylpalmitate, vinyl stearate;

'(c) Acrylic esters, such as ethyl acrylate, propyl acrylate, amylacrylate, heptyl acrylate, nonyl acrylate, undecyl acrylate, tetradecylacrylate, hexadecyl acrylate, octadecyl acrylate, ethenyl acrylate,dode'cenyl acrylate, octadecenyl acrylate;

(d) Allyl esters, such as allyl acetate, allyl butyrate, allylcaprylate, allyl caprate, allyl'laurate, allyl my-ristate, allylpalrnitate, allyl stearate;

(e) Allyl ethers, such as allyl ethyl .ether, allyl octyl ether, allyldodecyl ether, allyl tetradecyl ether, allyl hexadccyl ether, allyloctadecyl ether, allyl ethenyl ether, allyl octenyl ether, allyltetradecenyl ether, allyl octadecenyl ether;

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(f) Cycloaliphatic vinyl compounds, such as vinyl cyclohexene;

(g) Heterocyclic vinyl compounds, such as vinyl pyridine anddihydropyrane; and

(h) Alpha-olefins, such as ethylene, propylene, butene-l, octene-l,dodecene-l, tetradecene-l, hexadecene-l and heptadecene-l.

The copolymerization reaction is conducted under ordinary polymerizingconditions. Thus, the reactants may be heated together, either in bulk,or in the presence of a suitable solvent, such as benzene, toluene,xylene, acetone, dioxane or carbon tetrachloride, at temperaturesranging from about 50 C. to about 150 C. A polymerization catalyst ofthe peroxide type, such as benzoyl peroxide, is preferably used. Thereaction time varies from about 15 minutes to about 10 hours, althoughgenerally the reaction is complete in from about 1 to about 5 hours.

The preferred copolymers for the purpose of this invention are obtainedby reacting the monomers in substantially equimolar quantities.

The exact compositions of the copolymer products are not known. However,the molecular weights of the copolymers may be varied by varying thenature and amounts of catalyst used, the temperature, reaction time, orthe solvent. The preferred conditions in these respects are illustratedin the examples given hereinafter, but it is to be understood that theycan be varied to a considerable extent within the scope of thisinvention without making the products ineffective for the intendedpurpose. In general it is desirable that the copolymer have a fairlyhigh molecular weight, as this appears to increase its effectiveness,especially when the intended purpose is as a viscosity index impro er.

The aliphatic amines suitable for reaction with the above-describedcopolymers are the primary and secondary saturated aliphatic amineshaving from about 12 to about 18 carbon atoms, or a mixture of suchamines containing from 8 to 18 carbon atoms and an average of from 12 to14 carbon atoms per molecule. Typical of such amine reactants aredodecyl amine, tridecyl amine, tetradecyl amine, heptadecyl amine,hexadecyl amine, dioctyl amine, heptadecyl amine, octadecyl amine anddioctadecyl amine. Amines of the character useful in the invention aremarketed by Armour and Co.

under the Armeen trade name. These include:

Armeen CD (a mixture of C8 to C13 primary amines The copolymers may bereacted with one or two moles of the aliphatic primary or secondaryamine per mole of unsaturated polybasic acid or anhydride in thecopolymer. Thus, with the primary amine, either the imide or thediamide, or a mixture of the two, may be formed. However, with thesecondary amine, only the amide is formed, either the monoamide ordiamide depending upon the molar proportion used.

The reaction between the copolymer and the aliphatic amine is conductedsimply by heating the reactants together at moderate temperatures, i. e.fromabout C. up to about 200 C., until the reaction is complete.Generally, a solvent such as xylene, dioxane or the like is used, thetemperature of the reaction being the reflux temperature of the reactionmixture. The reaction is generally completed in from 1 to about 5 hours.The water of reaction is removed as the reaction proceeds by suitablemeans, such as a Dean-Stark trap. When the reaction is completed, thesolvent and unreacted amine are removed by distillation.

We have found that the effects provided by the copolymer-aminederivatives in oil vary depending upon the chain length of the primaryor secondary amine used. For example, when the amine contains 12 carbonatoms, the resulting product is oil-soluble but shows no effect as apour point depressant, although it is efiective as a viscosity indeximprover. However, when the amine contains 14 to 18 carbon atoms, theresulting product also functions as a pour point depressant. On theother hand, the use of a mixture of amines containing 8 to 18 carbonatoms and having an average of about 12 carbon atoms per molecule, suchas Armeen CD, also results in a product which functions both as aviscosity index improver and as a pour point depressant.

The following examples and results of tests will serve to illustratemore clearly the preparation and utility of the materials contemplatedherein.

EXAMPLE I Armeen CD derivative of maleic anhydride-vinyl acetatecopolymer A copolymer of maleic anhydride and vinyl acetate was preparedby reacting equimolar quantities of maleic anhydride and vinyl acetatein benzene solution using 0.25% benzoyl peroxide as catalyst.

Ten grams of this copolymer were suspended in 175 cc. of toluene and22.0 grams of Armeen CD (a mixture of C3 to C18 primary aliphatic amineshaving an average of approximately 12 carbon atoms per molecule) wereadded. The mixture was heated at reflux for 1 hour, the water ofreaction being removed by means of a Dean- Stark moisture trap. Thetoluene was then gradually distilled from the reaction mixture andreplaced with Sovasol 74, a high-boiling petroleum solvent. Thetemperature was raised to 140 C. and held about 2 hours. The solvent andunreacted amine were then distilled by heating to 150 C. at 1 mm.

EXAMPLE II Armeen 14D derivative of maleic anhydride-vinyl acetatecopolymer Ten grams of the vinyl acetate-maleic anhydride copolymerdescribed in Example I were suspended in 200 cc. of xylene and 100 cc.of toluene and 21.0 grams of Armeen 14D (a relatively puren-tetradecylamine) were added. The mixture was heated at reflux (125 C.)for 2% hours, the water of reaction being separated as previouslydescribed. The solvent was gradually distilled from the reaction mixtureand the temperature raised to 150 C. The residue was cooled, dilutedwith benzene and the solution was vacuum filtered. The solvent was thenremoved by distillation. The residue was finally extracted with hotmethyl alcohol to remove unreacted amine.

EXAMPLE III "Armeen 16D derivative of maleic anhydride-vinyl acetatecopolymer Four and two-tenths grams of the vinyl acetate-maleicanhydride copolymer described in Example I were suspended in 100 cc. ofxylene and 12.0 grams of Armeen 16D (a relatively pure n-hexadecylamine)were added. The action mixture was heated at 150 C. for 1 hour, thewater of reaction being separated as previously described. Xylene wasthen distilled from the reaction mixture and the temperature raised to200 C. After heating at this temperature for 1 hour, the mixture wastransferred to a distilling flask and heated to 260 C. at 1 mm. toremove unreacted amine.

EXAMPLE IV Armeen 18D derivative of maleic anhydride-vinyl acetatecopolymer Ten grams of the vinyl acetate-maleic anhydride copolymerdescribed in Example I were suppended in 200 cc. of xylene and 150 cc.of toluene and 27.0 grams of Armeen 18D (a relatively puren-octadecylamine) were added. The mixture was treated as described inExample II.

EXAMPLE V Armeen 14D derivative of maleic anhydride-vinyl Butyl ethercopolymer A copolymer of maleic anhydride and vinyl butyl ether wasprepared by reacting equimolar quantities of monomers in the presence of1.0% by weight of benzoyl peroxide and using a high boiling, highlyaromatic petroleum fraction (Sovasol 74) as solvent.

Ten grams of this copolymer, 20.0 grams of Armeen 14D and 200 cc. ofxylene were mixed and treated as described in Example III.

EXAMPLE VI Armeen 18D derivative of maleic anhydride-octene-I copolymerA copolymer of maleic anhydride and octene-l was prepared by heatingequimolar quantities of monomers in xylene at 120140 C. for 7 hoursusing 4.0% by weight of benzoyl peroxide.

Ten and one-half grams of this copolymer, 27.0 grams of Armeen 18D andcc. of xylene were mixed and heated at reflux for 3 hours, the water ofreaction being separated as previously described. The solvent was thengradually distilled from the reaction mixture raising the temperature to200 C. The residue was purified as described in Example II.

EXAMPLE VII Dioctadecyl amine derivative of maleic anhydride-vinylacetate copolymer Ten grams of the vinyl acetate-maleic anhydridecopolymer described in Example I, 25.0 grams of dioctadecyl amine, 200cc. of xylene and 100 cc. of toluene were mixed and treated as describedin Example II.

EXAMPLE VIII Dioctadecyl amine derivative of maleic anhydride-vinylbutyl ether copolymer Ten grams of the copolymer described in Example V,28.0 grams of dioctadecyl amine and 100 cc. of xylene were mixed andheated to reflux. Xylene was gradually distilled from the reactionmixture, thereby raising the reaction temperature to 200 C. Afterheating at this temperature for 1 /2 hours, the product was cooled andpurified as described in Example II.

EXAMPLE IX Diactadecyl amine derivative of maleic anhydrideoctene-Icopolymer Ten and one-half grams of the maleic anhydrideoctene-lcopolymer described in Example VI, 26.0 grams of dioctadecyl amine and100 cc. of xylene were mixed and treated as described in Example VII.

POUR POINT DEPRESSION The data in Table I illustrate the effectivenessof the products contemplated herein as pour point depressants. The pourdepressant effect of these products varies appreciably from oil to oilas indicated by the data, which show the results obtained in two oils.Oil A is a Duo-sol refined, Mid-Continent type oil of S. A. E. 30 gradehaving a Saybolt Universal Viscosity of 67 sec. 210 F. and an A. S. T.M. pour point of +20 F. Oil B is a furfural refined S. A. E. 10 gradeoil derived from Rodessa crude and having a Saybolt Universal Viscosityof 45.2 sec. at 210 F. and an A. S. T. M. pour point of +20 F.

Table I A. S. T. M. Pour Point, Concn., F. Product Blended in Oil Wt.Percent In Oil A In Oil B Example VII-.. 0.25 10 +20 Example VIII 0.25 5+20 Example IX 0.25 80 +5 V. I. IMPROVEMENT The eifectiveness of theproducts of this invention as viscosity index improvers is illustratedby the data in Table II. The results were obtained in an acid-refined,

Mid-Continent type oil stock having an original viscosity index of 81.1.

The proportions of the copolymer-amine product to be incorporated in alubricating oil will vary with the oil and with the desired improvement.Thus, concentrations of from about 0.01 to about 10% may be used,although the desired results are generally obtained with concentrationsof from 0.01 to 2.0%.

Instead of placing the products of this invention directly in thelubricating oil in which they are to be finally used, they may bemarketed as concentrates in mineral lubricating oil bases, suchconcentrates containing, say, 10% to 50%, or more, of the additive.

It is to be understood that the additive products of this invention maybe blended in lubricating oils containing other additives such as othertypes of pour point de- 6 pressants and viscosity index improvers,anti-rust agents, detergents, antioxidants, anti-foam agents, etc.

Although the principles of this invention have been illustrated hereinby means of certain specific examples and tests, it is not intended thatthe scope of the invention ble limited thereby, but only as indicated inthe following c arm.

This application is a division of application Serial No. 127,266 filedNovember 14, 1949, now abandoned.

I claim:

As a pour point depressant for mineral lubricating oils, a compositionproduced by reacting a heteropolymer of maleic anhydride and vinylacetate with a material consisting essentially of tetradecyl amine.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,047,398 Voss July 14, 1936 2,370,943 Dietrich Mar. 6, 19452,415,400 Armstrong Feb. 11, 1947 2,454,284 Kirk Nov. 23, 1948 2,456,177Cuprey Dec. 14, 1948 2,490,677 Cuprey Dec. 6, 1949 2,533,376 Jones Dec.12, 1950 2,615,845 Lippincott et al. Oct. 28, 1952

